Related papers: Gamma-ray bursts from synchrotron self-Compton emi…
The extreme energetics of the gamma-ray burst (GRB) 990123 has revealed that some of GRBs emit quite a large amount of energy, and total energy release from GRBs seems to change from burst to burst by a factor of 10^{2-3} as E_{gamma, iso}…
The gamma-ray burst GRB 180720B is very peculiar. On one hand, some interesting features have been found by performing the detailed time-resolved spectral analysis in the prompt phase. First, the `flux-tracking' pattern is exhibited both…
It has been suggested that the prompt emission in gamma-ray bursts consists of several components giving rise to the observed spectral shape. Here we examine a sample of the 8 brightest, single pulsed {\it Fermi} bursts whose spectra are…
Typical observational gamma-ray burst (GRB) spectra are discussed and, in this connection, what is the origin of the compactness problem and how it was solved at first. If the threshold for $e^{-}e^{+}$ pair production depends on an angle…
High energy emission (> tens MeV) of Gamma-Ray Bursts (GRBs) provides an important clue to understand the physical processes involved in GRBs, which may be correlated with the GRB early afterglow. A shallow decline phase has been well…
We compare the luminosity function and rate inferred from the GBM long bursts peak flux distribution with those inferred from the Swift and BATSE peak flux distribution. We find that the GBM, BATSE and the Swift peak fluxes can be fitted by…
The physical origin of gamma-ray burst (GRB) prompt emission (photosphere or synchrotron) is still subject to debate after five decades. Here, firstly we find that many observed characteristics of 15 long GRBs, which have the highest prompt…
Gamma-Ray Burst (GRB) afterglows are well described by synchrotron emission from relativistic blast waves expanding into an external medium. The blast wave is believed to amplify the magnetic field and accelerate the electrons into a power…
The recent launches of the Einstein Probe (EP) and the Space Variable Objects Monitor (SVOM) mission have led to the detection of a growing number of long GRBs with significant, early soft X-ray flux during their gamma-ray emission,…
In the framework of the internal shock scenario, we model the broadband prompt emission of gamma-ray bursts (GRBs) with emphasis on the GeV-TeV bands, utilizing Monte Carlo simulations that include various processes associated with…
The Fermi satellite has been reporting the detailed temporal properties of gamma-ray bursts (GRBs) in an extremely broad spectral range, 8 keV - 300 GeV, in particular, the unexpected delays of the GeV emission onsets behind the MeV…
The prompt emission of gamma-ray bursts (GRBs) is widely thought to be radiation from accelerated electrons, but an appreciably larger amount of energy could be carried by accelerated protons, particularly if GRBs are the sources of…
The recent detection of a gamma-ray flux from the direction of the Galactic center by EGRET on the Compton GRO raises the question of whether this is a point source (possibly coincident with the massive black hole candidate Sgr A*) or a…
Gamma Ray Burst prompt emission is believed to originate from electrons accelerated in a highly relativistic outflow. "Internal shocks" due to collisions between shells ejected by the central engine is a leading candidate for electron…
It is often stated that gamma-ray bursts (GRBs) have typical energies of several hundred keV. Is this a real feature of GRBs or is it due to an observational bias? We consider the possibility that bursts of a given bolometric luminosity…
We performed a time-resolved spectral analysis of 53 bright gamma-ray bursts (GRBs) observed by \textit{Fermi}/GBM. Our sample consists of 908 individual spectra extracted from the finest time slices in each GRB. We fitted them with the…
This paper introduces a kinetic code that simulates gamma-ray burst (GRB) afterglow emission from the external forward shock and presents examples of some of its applications. One interesting research topic discussed in the paper is the…
We considered a model for the prompt phase of Gamma-Ray Burst (GRB) emission arising from a magnetized jet undergoing gradual energy dissipation due to magnetic reconnection. The dissipated magnetic energy is translated to bulk kinetic…
Gamma Ray Bursts (GRBs) are among the most powerful sources in the Universe: they emit up to 10^54 erg in the hard X-ray band in few tens of seconds. The cosmological origin of GRBs has been confirmed by several spectroscopic measurements…
The mechanism responsible for the prompt gamma-ray emission of a gamma-ray burst continues to remain an enigma. The detailed analysis of the spectrum of GRB 131014A observed by the $Fermi$ gamma ray burst monitor and Large Area Telescope…